A study of air-to-ground sound propagation using an instrumented meteorological tower

The results of an exploratory NASA study, leading to a better understanding of the effects of meteorological conditions on the propagation of aircraft noise, are reported. The experimental program utilized a known sound source fixed atop an instrumented meteorological tower. The basic experimental scheme consisted of measuring the amplitude of sound radiated toward the ground along a line of microphones fixed to a tower guy wire. Experimental results show the feasibility of this approach in the acquisition of data indicating the variations encountered in the time-averaged and instantaneous amplitudes of propagated sound. The investigation included a consideration of ground reflections, a comparison of measured attenuations with predicted atmospheric absorption losses, and an evaluation of the amplitude fluctuations of recorded sound pressures

PVD Coatings’ Strength Properties at Various Temperatures by Nanoindentations and FEM Calculations Determined

Nanoindentation is usually applied on thin films at ambient temperatures for hardness determination. Recently, instruments for conducting nanoindentation at elevated temperatures have been developed facilitating measurements up to 700 oC. Both indenter and specimen, if necessary, are heated in an inert atmosphere to avoid film oxidations. In the described investigations, nanoindentations were conducted on cemented carbides and high speed steel specimens, coated with various films, up to 400 oC. The obtained results were subjected to statistical analysis to estimate their reliability. Moreover, the results were evaluated by appropriate FEM (Finite Element Method) algorithms for determining the coatings’ elasticity modulus, yield and rupture stress as well as hardness at various temperatures. The results reveal a non-linear temperature dependence of the coating properties

Acoustical characteristics of the NASA Langley full scale wind tunnel test section

The full-scale wind tunnel at NASA-Langley Research Center was designed for low-speed aerodynamic testing of aircraft. Sound absorbing treatment has been added to the ceiling and walls of the tunnel test section to create a more anechoic condition for taking acoustical measurements during aerodynamic tests. The results of an experimental investigation of the present acoustical characteristics of the tunnel test section are presented. The experimental program included measurements of ambient nosie levels existing during various tunnel operating conditions, investigation of the sound field produced by an omnidirectional source, and determination of sound field decay rates for impulsive noise excitation. A comparison of the current results with previous measurements shows that the added sound treatment has improved the acoustical condition of the tunnel test section. An analysis of the data indicate that sound reflections from the tunnel ground-board platform could create difficulties in the interpretation of actual test results

Young adults' perceptions of using wearables, social media and other technologies to detect worsening mental health: A qualitative study

BACKGROUND: Technological interventions may help support and improve mental health. However young peoples' perspectives on using different technologies to detect deteriorating mental health in those already diagnosed with a mental health condition is lacking. The study aim was to explore the perspectives of young patients on the feasibility and acceptability of using wearables, social media and technologies to detect mental health deterioration. METHODS: The study was co-produced with young adults with past mental health difficulties. Semi-structured interviews were conducted with young adults with a severe mental health condition in a private room at a community mental health site. Data was triangulated by comparing codes and ideas across the two co-researchers and two researchers over two virtual meetings. Themes were finalised and presented in a thematic map. RESULTS: Sixteen participants were interviewed (81% female). There were four main themes: dealing with mental health symptoms, signs of mental health deterioration, technology concerns and technological applications to identify worsening mental health. Wearables and mobile apps were considered acceptable and feasible to detect mental health deterioration in real-time if they could measure changes in sleep patterns, mood or activity levels as signs of deterioration. Getting help earlier was deemed essential particularly in reference to dissatisfaction with the current non-technological mental health services. However, patients identified issues to consider before implementation including practicality, safeguarding and patient preference. CONCLUSION: Wearables and mobile apps could be viable technological options to help detect deterioration in young people in order to intervene early and avoid delay in accessing mental health services. However, immediate action following detection is required for the patient to trust and use the intervention

Small molecule additive for low-power accumulation mode organic electrochemical transistors

A small molecule additive, dodecylbenzenesulfonate (DBSA), is added to the electrolyte in OECTs to improve the device performance.ERC IMBIBE EPSRC CDT Plastic Electronic

Transcranial direct current stimulation with functional magnetic resonance imaging: a detailed validation and operational guide [version 1; peer review: 1 approved with reservations]

Introduction: Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique used to modulate human brain and behavioural function in both research and clinical interventions. The combination of functional magnetic resonance imaging (fMRI) with tDCS enables researchers to directly test causal contributions of stimulated brain regions, answering questions about the physiology and neural mechanisms underlying behaviour. Despite the promise of the technique, advances have been hampered by technical challenges and methodological variability between studies, confounding comparability/replicability. / Methods: Here tDCS-fMRI at 3T was developed for a series of experiments investigating language recovery after stroke. To validate the method, one healthy volunteer completed an fMRI paradigm with three conditions: (i) No-tDCS, (ii) Sham-tDCS, (iii) 2mA Anodal-tDCS. MR data were analysed in SPM12 with region-of-interest (ROI) analyses of the two electrodes and reference sites. / Results: Quality assessment indicated no visible signal dropouts or distortions introduced by the tDCS equipment. After modelling scanner drift, motion-related variance, and temporal autocorrelation, we found no field inhomogeneity in functional sensitivity metrics across conditions in grey matter and in the three ROIs. / Discussion: Key safety factors and risk mitigation strategies that must be taken into consideration when integrating tDCS into an fMRI environment are outlined. To obtain reliable results, we provide practical solutions to technical challenges and complications of the method. It is hoped that sharing these data and SOP will promote methodological replication in future studies, enhancing the quality of tDCS-fMRI application, and improve the reliability of scientific results in this field. / Conclusions: The method and data provided here provide a technically safe, reliable tDCS-fMRI procedure to obtain high quality MR data. The detailed framework of the Standard Operation Procedure SOP (https://doi.org/10.5281/zenodo.4606564) systematically reports the technical and procedural elements of our tDCS-fMRI approach, which we hope can be adopted and prove useful in future studies

Равновесие и динамика адсорбции паров воды на металлорганическом каркасе MOF-801

В работе представлены результаты исследования равновесия и динамики адсорбции паров воды на металлоорганическом каркасе MOF-801 с целью оценки потенциала его применения в системах адсорбционного охлаждения. Показано, что адсорбция воды на MOF-801 характеризуется S-образными изобарами IV типа по классификации ИЮПАК. В условиях типичного рабочего цикла адсорбционного холодильника (АХ) MOF-801 обменивает 0,21 г/г и может быть регенерирован при 80-85°С, что позволяет использовать источники низкотемпературной теплоты (солнечная энергия). Динамика адсорбции на гранулах MOF-801 в условиях рабочего цикла АХ происходит в режиме, при котором скорость процесса определяется отношением S/m площади поверхности теплопереноса S к массе адсорбента m. Эффективность и удельная мощность АХ с использованием пары "MOF-801-вода" достигают 0,67 и 2 кВт/кг соответственно, что представляет большой практический интерес

In-Vacuum Photogrammetry of a 10-Meter Solar Sail

In July 2004, a 10-meter solar sail structure developed by L Garde, Inc. was tested in vacuum at the NASA Glenn 30-meter Plum Brook Space Power Facility in Sandusky, Ohio. The three main objections of the test were to demonstrate unattended deployment from a stowed configuration, to measure the deployed shape of the sail at both ambient and cryogenic room temperatures, and to measure the deployed structural dynamic characteristics (vibration modes). This paper summarizes the work conducted to fulfill the second test objective. The deployed shape was measured photogrammetrically in vacuum conditions with four 2-megapixel digital video cameras contained in custom made pressurized canisters. The canisters included high-intensity LED ring lights to illuminate a grid of retroreflective targets distributed on the solar sail. The test results closely matched pre-test photogrammetry numerical simulations and compare well with ABAQUS finite-element model predictions

Reflections, impact and recommendations of a co-produced qualitative study with young people who have experience of mental health difficulties

Background: There is limited evidence of genuine equal partnership where power is shared with young people with mental health difficulties throughout all research stages, particularly in data collection and analysis. Objective: To describe how our qualitative study, exploring young peoples’ perceptions on the feasibility of using technology to detect mental health deterioration, was co- produced using principles of co-production, whilst reflecting on impact, challenges and recommendations. Methods: Young people with experience of mental health difficulties were appointed and then worked with researchers throughout all research stages. The study was evaluated against the five principles of co-production. Reflections from researchers and young people were collected throughout. Results: Seven young people formed an initial Young People's Advisory Group (YPAG); three became co-researchers. Reflection was key throughout the process. Sharing power became easier and more evident as trust, confidence and mutual re- spect grew over time, particularly after a safe space was established. The safe space was crucial for open discussions, and our WhatsApp group enabled continual com- munication, support and shared decision-making. The resulting co-produced topic guide, coding framework, thematic map, papers and presentations demonstrated significant impact. Conclusions: To our knowledge, this is the first qualitative mental health study to be co-produced using the principles of co-production. Our rigorous assessment can be utilized as an informative document to help others to produce meaningful co- produced future research. Although co-production takes time, it makes significant impact to the research, researchers and co-researchers. Flexible funding for spon- taneous suggestions from co-researchers and more time for interview training is recommended